熔融耦合器中耦合模式与新型孤子结构  

Coupled mode and novel soliton structure in fused coupler

作　　者：李森清 张肖 林机[1] Li Sen-Qing;Zhang Xiao;Lin Ji(Department of Physics,Zhejiang Normal University,Jinhua 321004,China)

机构地区：[1]浙江师范大学物理系,金华321004

出　　处：《物理学报》2022年第23期280-287,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11835011,12004338)资助的课题。

摘　　要：研究了非局域非线性熔融耦合器的耦合模式构建新型孤子结构和稳定性的关联性.对于高斯型耦合模式,存在多极类亮孤子、平顶孤子和多极灰孤子结构.一至三极对称峰值的类亮孤子、灰孤子和平顶孤子传播是稳定的,孤子峰值不同的三极类亮孤子和三极灰孤子均不能稳定.研究发现灰度将影响灰孤子传播的稳定性.通过调制耦合函数宽度,可实现孤子结构的转换.In this paper,we investigate the characteristics of bright-like solitons,flat-topped solitons,and gray solitons in nonlocal nonlinear fused coupler.Firstly,the fundamental bright-like solitons with different parameters are obtained by the Newton iteration.It is found that the peak value and beam width of the ground state bright-like soliton increase with the enhancement of the nonlocality degree and nonlinear parameter,and they decrease with the propagation constant increasing.The power of the ground state bright-like soliton increases with the increase of the nonlocality degree and the width of coupling function,and it decreases with the propagation constant increasing.These numerical results can also be verified in the case of multipolar bright-like solitons.Secondly,by changing the coupled mode,the solutions of multipolar bright-like solitons,flat-topped soliton and grey solitons are obtained.The transmission stability of multipolar bright-like solitons,flat-topped soliton and grey solitons are studied.The stability of solitons is verified by means of linear stability analysis and fractional Fourier evolution.In the process of long-distance propagation,the propagation of bright-like solitons,gray solitons,and flat-topped soliton with one to three-pole symmetric peaks are stable,and the tripolar bright-like solitons with different soliton peaks and tripolar gray solitons are unable to transmit steadily.At the same time,it is found that the gray soliton with three poles or more is not easy to maintain its transmission stability.It is also found that the higher the grey scale of the gray soliton,the easier it is to realize stable transmission.Finally,it is found that the coupling function width not only affects the power of the soliton,but also realize the conversion among different soliton structures by adjusting the coupling function width.

关 键 词：非局域 光孤子结构 耦合模式 稳定性 

分 类 号：O437[机械工程—光学工程]